In the frog cornea, there is substantive evidence that the maintenance of corneal transparency is a direct consequence of both active transepithelial Cl, Na transport, and metabolism. The purpose of this study is to characterize the coupling between metabolism and active Cl, Na transport. Such a characterization is of interest for understanding the contribution of particular metabolic pathways in supporting active Cl and Na transport and also for estimating the energetic requirements of the transport processes. Our experimental approach consists of two procedures; namely to evaluate whether altering the rates of metabolic pathways effects the rates of active Cl and Na transport and secondly the converse procedure. Using the first procedure, the contribution of particular metabolic pathways in supporting active C1 and Na transport is being evaluated. Should the first procedure demonstrate a positive correlation between the rates of a particular metabolic pathway and active Cl and Na transport, then the second procedure is used to evaluate the energetic requirement of active Cl and Na transport (i.e. the energy required to transport a mole of Cl or Na). Three metabolic pathway rates are being characterized and where possible their rates are being measured in parallel with the short-circuit current (i.e. active Cl, Na transport rate). These pathways are glycolysis, respiration, and pentose shunt.